The invention relates to an inflatable airbag for the protection of a person. Further, the invention relates to an airbag module comprising such airbag. Finally, within the scope of the invention, a vehicle occupant restraint system comprising an airbag or an airbag module is stated. Furthermore, the invention relates to a method of manufacturing an inflatable airbag.
An airbag of the type mentioned in the beginning is known from WO 2012/044245 A1, for example. The known airbag is part of a protective device for the head of a person which includes the airbag as well as an outer cover. The airbag comprises a flexible cover having finger-type extensions, which delimits a closed gas expansion compartment, and is embedded in an outer bag made from gas-permeable material, wherein the individual fingers of the cover engage in receiving pockets of the outer bag. The outer bag is provided to predetermine the shape of the protective device in the inflated state of the airbag. In other words, the outer bag restricts the expansion of the inner airbag, especially of the finger-type extensions of the inner airbag. This ensures that the protective device takes the desired shape in the inflated state, in the known protective device this shape is configured especially in the way of a bicycle helmet so that the inflated airbag encloses the person's head like a helmet.
It is a drawback of the known protective device that a relatively great effort has to be made to manufacture the inner airbag and the outer bag. The functional separation of the inflatable airbag and the shaping outer bag results in a relative complex design of the protective device and increases the production expenditure. Finally, this results in increased manufacturing costs.
In the protective device known from the state of the art it is necessary that in the case of operation all finger-type extensions have to be inflated with gas. If the concept of WO 2012/044245 A1 is applied to vehicle occupant restraint systems, it is necessary to provide an inflator which fills all finger-type extensions of the inflatable airbag with gas, with the finger-type extensions forming a relatively large gas expansion compartment.